/**
 * @User: vitobo
 * @Date: 2024-05-31
 * @Description:
 *
 *  通配符
 *      ?
 *
 */
class Message<T>{
    private T message;
    public T getMessage(){
        return message;
    }

    public void setMessage(T message){
        this.message = message;
    }
}

public class Test3 {
    public static void fun(Message<?> tmp){
        System.out.println(tmp.getMessage());
    }

    public static void main(String[] args) {
        Message<Integer> message = new Message<>();
        message.setMessage(10);
        fun(message);
    }

}
